Method of concentrating ores.



PATENTED NOV. 19, 1907.

A. SOHWARZ.

METHOD OF CONOENTRATING ORES.

APPLICATION FILED OCT 27, 1906.

2 SHEETS-SHEET 1.

INVENTOR 77 Lf%w W ATTORNEYS WITNESSES:

PAT-ENTED NOV. 19, 1907.

A. SOHWARZ.

METHOD OF OONGENTRATING ORES.

APPLIOATION FILED 0GT.2'1, 1906.

2 SHEETS-SHEET 2.

WITNESSES:

UNTE

ALFRED SGHWARZ, OF NEW YORK, N.1Y.

' METHOD OF CONCENTRATING- ORES.

K en-36s,

To all whom it may concern:

Be it known that I, ALFRED SOHWARZ, a subject of the Emperor of Germany, residing at NewYork city, in the county of New York and State of New York, have invented certain new and useful Improvements in Method of Concentrating Ores, of which the following is a specification.

My invention relates to a method of concentrating ores all as fully described herein: after. v

In the previous practice of concentrating ores the surface of the concentrating tables is divided by lon itudinal, wooden strips, sometimes of equa sometimes of unequal length, the length in the latter construction increasing from the upper to the lower side,

ofthe table. zThese strips or riflles have been made substantially rectangular in section. The tables are inclined transversely, and in operation the ore in the form of pul is introduced at the higher side near one en I and under the action of the wash water and the reclprocations of the table the ore is carried transversely downward and longitudinally forward, the \purpose' bein that the gangue shall be discharged at thelower edge of the table, while the values or concentrates are discharged at the foot of the table. The lighter portion of the gangue passes over each rifile in succession while the values and the heavier gangue are caught by the riflles and carried toward the foot of the table.

The function of the riffies is to catch and re- "tunity tain the values and confine their movement to one longitudinal of the table; but, owing,

to the comparatively great width of the riifies and their depth as compared with the particles of ore, masses f the latter become particles.

The presence of obstructions in the form of riflies to check the travel of the ore pulp has heretofore been considered essential tdthe successful operation of a gravity concentrating table. I havefound, however, that it is necessary to have a substantially continuous and unobstructed flow of water over a surface that offers no opportunity for the piling up or even stoppage of either gangue or values and to guide the heavy mineral particles in the direction of movement of the ta- Specification of Letters Patent. Application; ilef October 27. 1906. Serial No. 340-863.

for the escape of the finer metallic Patented Nov. 19, 1907.

the flow of Water) in such a manner as not either-to disturb substantially the even flow of water or to offer obstruction to the cles of gang'ue carried thereby.

A further advantage of my method .of treatment is dependent upon these facts In pulverizing the orespreparatory to subjectmg them to concentrating operatlons it is found that the values are ground finer than the gangues, which are, on the average, of harder composition.- Hence, when the mass is ground to 30 mesh or 40 mesh, it is,

in general, the gangues-e. g. silicathat compose the bulk of the particles that are of about the caliber of the screen, while the values are mostly among the finer particles. These large particles, onaccount of their size, will act as heavier material in gravity processes; and tend to find lodgment at any obstruction, whereby they retard all the finer particles and prevent their separation.

I have found that if the surface upon which the operations are taking place be rovided with a series of fine indentations su cient to act as guides for the mineral plarticles, but ofism and a plurality of ore concentrating tables fed therefrom, the mechanism being reppartiagrammatic and conresented as reducing the ore to various.

meshes, and deliverin ores of different meshes to different tab es.

represent the corrugated surfaces of the threedifl'erent tables illustrated in Fi 1..

sponding parts in the several figures of the drawings. I

1 represents an ore'crushing-or grinding machine from which the crushed-ore is deble (which is substantially at right angles to livered, through a pipe 2, to -a hopper 3,

Figs. 2, 2, 2

Fig. 5 is a through which it falls upon the highest. of a series of screens 4:, 5, 6, which are kept in agitation by any suitable means, as will be read ily understood. Water may be fed to these screens through the pipes 11, operatively' connected with a pump 12. Particles too large to gothrough the upper, and coarsest,

screen 4, may be Washed orshaken back into a pipe 7, and .carried back to the grinder.

In the normal operat on of the machine,

the finest particles will pass in succession through all three screens, and fall from the thesezdifferences' being illustrated inFigs. 2.,

lowest into a hopper 10,, whence. they are car ried'to a pipe 13 that leads to a concentrating table 14". In like manner the screenings from 5 and 4 are carried through pipes 9 and 8 to other tables 14' and 14. The meshes of the screen 5 are less than those of screen 4, and screen 6 is of still finer mesh than '5. The tables 14, 14 and 14", have their 0 crating surfacescorrugated, as will be more ully described, the corrugations beingpro ortione'd to the mesh offthe-screen's from w 'ch they 1 are fed. Thus,as suming screens 4, 5 and 6- to be of 30, and 60 mesh, respectively, the surfaces of tables 14, 14 14 will have 8, '12and 15 corrugations per inch-respectively,

2'? and2 Y .Figs. 3 and t illustrate more fully the constructlon andj arran ement of the tables 14,

it being understood, owever, that the corrugat ons ind cated at..1 8 in Fig. 3 areprop'or tionately' far larger than are used on such a table as is there represented, which is in the neighborhood of 6 feet inlwidth. 1 The table is. suitably mounted as on rollers 15 running upon track 1 6 so that it may be given a longitudinal reciprocating movement which rnav ployed. The table is preferably inclined. slightly transversely of its length, as is illustrated in Fig. 4, and in'describing it-I shall be imparted to it by any suitable means, such as that illustrated at 17. A head motion to impart a differential "reciprocating movement, well understood in this art, will be e1'n-.

- the discharge of the ore-pulp upon the corrugated surface 1'8. Extending along a part of .the. higher side of the table 14 is a erforated Water supply ipe.22, which is so isposed'as to discharge t e wash water issuing from the perforations thereof against the vertical wall 19 extending around the higher side of the table, so. as not to splash the water over the corrugated surface which would create an un- I have ,obt'aine desirable disturbance of the masses of ore and concentrates thereon. A short distance back of the foot of the table, and extending transversely thereof, is a water discharge pipe 23,

the perforations of.which direct the flow of water toward the foot of the table so as .to

tend to Wash it clear and carry the values into the trough 24.

Secured to the lowerside of the table is a j trough 25 adapted to receive gangue or tailings, said trough being inclined downwardly toward the head of the table and discharging into a settling tank 26. The trough.24' at the foot. of the table extends transversely across it and connects with the settling tank 27, into which it discharges the values or con.

centrates. Between the troughs 24 and 25 is a short trough 28, which receives the middlings and discharges them into a settling tank 29. The lengths of the troughs 25 and 28 may be-varied to suit conditions met with in the treatment of different ores.

The pipes 22, 23 may be connected with a pump or other suitable source of water supply,

and the trough or hop er 20 is similarly supplied}. As Wlll be rea ily understood, a com plete. water. circulating system may be 'used whereby the Water'running into the settling tanks 26, 27 and 29. may be drawn off and run back into the pipes 22, 23 and the trough 20.

Instead of having a single pipe 22 extending along the upper side of the table I may provide separate discharge pipes 22, 22 so as to have separate regulatlon ofthe Water supply at different points of the table.

Ashas been stated before, the surface of the table is provided; with indentations or corrugations-18 which extend preferably in thedirection of thereciprocating movement imparted to the/table as above described.

These corrugations may be mere lines or scoringqs cut into or raised upon the surface of the ta le, which will be sufiicient to act as guides for the heavier articles ofore, or values; but

5 the best results when these indentations or corrugations have an appreciable depth andf'width that bears a certain relation to the mesh of the ore',-- (*5.- e. the size of the larger particles of gangue). Praetical experience. suggests that, for 30 mesh ore there should be 8 corrugations per inch:

for 40 mesh ore, 12 corrugations per inch;-

for 60 mesh ore, 15corrugations; and for 80 I mesh, 20 corrugations.

In Figs. 1 and 2, 2?, 2'', I have illustrated proper means for separating, handling and concentrating 30, 40 and 60 mesh ores. The proportions stated are not absolute but it is of the greatest importance that the width and depth of the corrugations shall be so proortioned to the mesh of the ore that the arger particles of the latter do not form obstructions or dams upon the table, the avoi 'ance of eddies in the flow of water being of great importance. So far as my experience tations from 1/25 to 1/40 of 'an inch deep; and as. a general rulethe Width of the inden- I tations is about three times the diameter of the larger particles, and the depth less than the width- It is not necessary that the corrugations.

shall be in the direction of agitation alone, or even that they shall be exactlyin that direction. For example, there maybe sev eral series of intersecting corrugations, or a single series running at an angle of less than 90 degrees to the direction oifiowof water.

In the ractice of my method upon the apparatus have described and illustrated, the

ore is pulverized in the crusher 1, and after being screened .upon the screens 4, 5 and 6, or some of them, is fed to the tables 14, &c., falling into the hopper 20 at the upper side of the table near the head. From this hopper the ore, which is in the form of pulp,

being mixed with water during or after the I operations of grinding and screening, falls upon the corrugated surface of the. table which is being'agitated or moved backward and forward longitudinally. At the same the pipes 22, 22* and the trough 20 in such quantity-and. at such a rate as to make an even and uninterrupted current down the table ,from the upper to the lower side. The mass of ore pulp begins to work in a general diagonal. direction across the surface of the table, this. direction being varied to some extent vby regulating the flow of water from the rear section of pipe 22; Y The current of water.v

at once washesout of the mass of ore a large part of the ganguaand carries it over to the trough 25, whence it flows into the tank 26. The concentrates, on theother hand, by the reciprocations of the table and guided by the corrugations 18,- move down toward the foot of the table.- I If theguides 18 are in the form of corrugations the small {particles of values fall into them and progress toward the foot of the table until they are caught by the wash .of water from the pipe 23 and swept into the trough 24, thence. into the tank 27. If the guidesiSare mere scorings or lines upon the surface of thetable, the travel of the (DODGE-I14 that the values have .a-

the advantages of my process is that by a I single operation a plurality of metals of different specific gravities will be separated from a single composite ore, and may be taken off at difierent points of the field.

In the construction shown in the drawin the values, by reason of their greater specific gravity, tend to settle in the corrugations near the upper side of the table and over a well defined area; and as they are then free from any disturbing influence except that which tends to. move them toward the foot of the table, they will be carried off to the concent'rate tank without loss such as has been 4 occasioned in former treatments 'by the formation of dams andeddies due to the lodg ment of large particles of ganguex The body that continues to move diagonally acrossthe table tends to spread out in a fan-like mass,"

the characteristic of which is that the values .are held or tend to fall into the corrugations toward its higher side, while the gangue is being constantly carried ofi by the current of water down toward the trough-25. In

this operation there is a substantiallv uniwater .carrying particles 'of form flow of gangue from the upper'to the-lower side. of

-.the table, and a substantially uninterrupted progression-of the values down the guides or corrugations 18 to the foot of the table. time water is supplied to the table'through The observed, behavior of the corrugated surface above described is substantially different from that of a table having'rifiles in' that the corrugations tend toward the maintenance of bodiesor zones of water which are substantially quiescent-in planes transverse to the corrugations andin which ion the separated metallic values are protected from, while' the gangue. is exposed};.to the currents of'washwater, the values" being free to move in these protected tudin'ally of the corrugations.

Another -factor incident to the. resent invention and which adds to its ut1ity,.is that the corrugations are. so. proportionedparing the ore,-it is obvious that any means whereby the ore is reduced'to-a certain maximum mesh will be sufficient for this step .in In process. tratesis in-less'definite paths, there being field will answer the purpose, provided it be supplied with a uniform flow-of water in one roportionately pprticles of gangue. 1 1 ed certain instru'-;.

iris zones longidirection and be agitated in another, there being guides to direct the movement of the heavier particles in substantially the d1I'80- tion of agitation. For the surface of the table or other field I have used lead, since, being so ft, it is easily corrugated by being passed between suitable rolls. I may, however, use materials such as glass, which may be molded in one piece, or aluminium, or even vulcanized rubber. I prefer, however, an electro deposited covering. of copper formed upon a suitable matrix; this covering may be made in one piece, thus dispensing with the necessity ofi joints or seams which create undesirable'local disturbances in the current of water. The electro-deposited covering of copper is particularly advantageous when it is desired to v have corrugations such as are shown in Fig. 4or Fig. 5.. In Fig. 5 it will be understood the parts are indicated on a greatly enlarged scale for the purpose of showing how the values 30 settle 1n the hollows, while the current of water carries the large particles of gangue 31 over the tops of the corrugations. l

' What I claim and desireto secure by Letters Patent of the United States is:

The rocess of concentrating ores consisting H1 sizing the ore and flowing each size in a ulp current over bodies of liquid restrained from movement in planes in the direction of gravital flow, inclosing the values in the quiescent liquid, and differentially agitating the whole to promote settling and to convey the settled values in directions other than that of gravital flow, and gravitally washing away the gangue.

In testimony whereof I have hereunto signed my name in the presence of two subscribing witnesses; V

i ALFRED SCHWARZ.

Witnesses:

' M. LAWSON DYER,

CHARLES S. JONES. 

